The present invention relates to an aerially-visible-image formation device for allowing a visible image, such as character or video, to be drawn in the air by using laser beams.
In recent years, there has been a skyrocketing expansion in the prevalence of three-dimensional liquid crystal TVs. In these three-dimensional liquid crystal TVs, two-dimensional images equipped with a stereoscopic parallax are displayed alternately. Moreover, these images displayed are watched alternately with right and left eyes via such tools as polarization spectacles. This method allows the stereoscopic effect to be visually recognized in these three-dimensional liquid crystal TVs. In this method, however, there exist the following problems: Namely, only the three-dimensional information in the range of about a both eyes' parallax angle can be visually recognized. Furthermore, the visually-recognized position is limited. Also, holography is practically utilized for forgery prevention in paper money and card.
In addition thereto, there exist various three-dimensional-image display technologies. For example, in JP-A-3-107120 and JP-A-5-224608, the disclosures have been made concerning three-dimensional-image formation technologies for forming a three-dimensional image in space.
In more detail, the three-dimensional-image formation technology disclosed in JP-A-3-107120 is as follows: Namely, an area where an excitation substance is distributed is irradiated with two types of beam-like invisible lights. As a result, the two-stage excitation phenomenon of the excitation substance is caused to occur at an intersection point of these two types of light beams. Moreover, a visible light (i.e., excited-radiation light) is emitted from the excitation substance when this substance returns from its excited state to its stable state (i.e., its ground state). Finally, the three-dimensional image is formed at the light beams' intersection point by utilizing this visible light emitted, and operating the two types of scanning light beams.
Also, the three-dimensional-image formation technology disclosed in JP-A-5-224608 is as follows: Namely, two pieces of two-dimensional laser arrays are deployed in such a manner as to become perpendicular to each other. Moreover, the three-dimensional image based on a fluorescent light is formed at the laser lights' intersection point by operating the scanning laser arrays. Here, this fluorescent light is emitted in a relaxation process during which the excited state relaxes.